
const readline = require("readline");
const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
});

let input_arr = []
rl.on('line', function (line) {
  input_arr.push(line)
}
);

rl.on('close', function () {
    let count = parseInt(input_arr[0])
    =[]
    for(i=0;i<count;i++){
        let arr=input_arr[i+1].split(' ')
        let student_infos_object={
            sex:arr[0],
            student_name:arr[1],
        }
        student_infos_arr.push(student_infos_object)
    }
    let girls=student_infos_arr.filter((item)=>item.sex==='0')
    let boys=student_infos_arr.filter((item)=>item.sex==='1')
    let pair_count=0
    for(i=0;i<student_infos_arr.length;i++){
        if(pair_count===count/2){
            break
        }
        let student_infos_object=student_infos_arr[i]
        if(student_infos_object.sex==='0'){
            let boy=boys.pop()
            console.log(`${student_infos_object.student_name}${boy.student_name}`);
        }
        else if(student_infos_object.sex==='1'){
            let girl=girls.pop()
        console.log(`${student_infos_object.student_name}${girl.student_name}`);
    }}
})
